Method for sulphonylating a hydroxylated organic compound

ABSTRACT

The invention concerns a method for sulphonylating a hydroxylated organic compound. The invention concerns in particular aliphatic hydroxylated compounds and more particularly those which comprise on their aliphatic chain, an electroattractive group. The method for sulphonylating a hydroxylated organic compound is characterised in that it consists in reacting said compound, with a sulphonylating agent, in the presence of a sufficient amount of a Lewis acid.

[0001] The present invention relates to a process for sulphonylating ahydroxylated organic compound. More particularly, the invention relatesto aliphatic type hydroxylated compounds, more particularly thosecomprising an electron-attracting group in their aliphatic chain.

[0002] Preferably, the invention is applicable to perfluorinatedaliphatic alcohols, in particular 2,2,2-trifluoroethanol.

[0003] Crossland et al. have shown that2,2,2-trifluoroethylnethanesulphonate, abbreviated to “TFEMes” forsimplicity, can be prepared by reacting 2,2,2-trifluoroethanol withmesyl chloride in the presence of a base such as triethylamine and in anorganic solvent, namely dichloromethane.

[0004] The disadvantage with that process is that it is difficult toscale up to an industrial level as it results in poor productivitybecause of the extremely dilute reaction medium, and it also results inhighly polluting discharges due to the presence of large quantities ofammonium salt.

[0005] The aim of the present invention is to provide a process that canovercome the disadvantages cited above.

[0006] We have now discovered, and this forms one aspect of the presentinvention, a process for sulphonylating a hydroxylated organic compound,characterized in that it consists of reacting said compound with asulphonylating agent in the presence of an effective quantity of a Lewisacid.

[0007] In the present text, the term “Lewis acid” means a compoundcomprising a metal or metalloid cation that is an electron pairacceptor, which reacts with the sulphonylating agent rather than withthe hydroxylated organic compound.

[0008] Regarding the choice of metal or metalloid cation, referenceshould be made to the “hard” and “soft” classification defined by RPEARSON in the Journal of Chem. Ed. 45, pages 581-587 (1968).

[0009] Borderline or the like metal or metallic cations are used, theterm “borderline” being used as defined in the reference cited above.

[0010] The term “borderline” as used in the present invention means notonly metal or metalloid cations classified as borderline, but also allthose classified as hard or soft with the exception of very hard andvery soft cations.

[0011] The term “hard cation” defines an electron-accepting atom whichmay be large or small and has a large positive charge which does notcontain unpaired electrons in its valency orbital. They are generallysmall cations with a high oxidation number which do not have readilyremovable electrons.

[0012] Examples of very hard cations that can be cited are B³⁺, Mg²⁺,Al³⁺, Si⁴⁺, Ti⁴⁺, Mn²⁺, Fe³⁺, Zr⁴⁺ and La³⁺.

[0013] The term “soft cation” means an electron-accepting atom which maybe large or small and which has a small positive charge, which containsunpaired electrons (p or d) in the valency orbital. They are generallylarge cations with a low oxidation number with readily removableelectrons.

[0014] Examples of very soft cations that can be mentioned are Cu⁺, Ag⁺,Hg⁺.

[0015] Regarding the choice of a borderline cation as defined in theinvention, reference should be made to the literature, in particular tothe article by TSE-LOK HO [Chemical Reviews 75, n°1, pp 1-20 (1975)].

[0016] The borderline cation employed in the process of the inventionhas an oxidation number of at least +2, preferably +3, +4 or +5.

[0017] Suitable metal or metalloid cations that can be cited inparticular are those of metal or metalloid elements from groups (IIb),(IVb), (Vb) and (VIb) from the periodic table.

[0018] In the present text, a reference to the periodic table will referto that published in the Bulletin de la Société Chimique de France, n°1(1966).

[0019] Particular examples of cations suitable for use in the process ofthe invention that can be cited are those from group (IIb), zinc; group(IVb), tin; group (Vb), antimony, bismuth; group (VIb), tellurium.

[0020] Preferred cations from those cited above are Zn²⁺, Sn²⁺, Sn⁴⁺,Sb⁵⁺, Bi³⁺, Te⁴⁺, and still more preferably Sb⁵⁺.

[0021] The nature of the anions bonded to said cations allows thehardness or softness of the cation to be adjusted.

[0022] Hard anions, in particular SO₄ ²⁻, CH₃COO⁻, C₆H₅COO⁻, CH₃SO₃ ⁻,CF₃SO₃ ⁻, CF₃C₆H₄SO₃ ⁻ or borderline anions such as Cl⁻, Br⁻, NO₂ ⁻ orSO₃ ²⁻ can be mentioned.

[0023] Preferred anions from those cited above are Cl⁻ and Br⁻.

[0024] More specific examples of Lewis acids that can be mentioned areorganic salts such as the acetate, propionate, benzoate,methanesulphonate, trifluoromethanesulphonate of metal or metalloidelements from said groups from the periodic table.

[0025] Regarding the inorganic salts, the chloride, bromide, iodide,sulphate, oxide and analogous products of the metal or metalloidelements from said groups can be cited.

[0026] Preferably, metal halides are selected, more particularlyantimony (V), tin (II) or (IV), zinc (II), bismuth (III) or tellurium(IV) chloride or bromide.

[0027] It is possible to generate a halide in situ and thus, anycompound of the elements cited above can be used, provided that it isassociated with a source of a halogen.

[0028] The metal can be used in any form. They can be supplied in theform of the metal or the oxide or in the salt form, either a simple ordouble salt, mineral or organic. It is possible to use a mineral salt,preferably a nitrate, sulphate, oxysulphate, halide, oxyhalide,silicate, carbonate, oxalate or an organic salt, preferably theacetylacetonate; or an alcoholate, still more preferably the methylateor ethylate; carboxylate or still more preferably, the acetate.

[0029] Regarding the source of the halogen, any compound can be usedwhich can supply halogen ions that can generate the metal or metalloidhalide in situ.

[0030] Examples of halogen sources that can be cited are the molecularform of the halogen; any mineral or organic acid halide, moreparticularly of aliphatic carboxylic acids; and any mineral or organicmetal or metalloid salt that can generate a halogenated form.

[0031] More specific examples that can be mentioned include the chlorideor bromide; hydrochloric acid, hydrobromic acid; acetyl chloride;silicon chloride SiCl₄, halogenosilanes such as Me₃SiCl, Me₂SiCl₂,MeSiCl₃, PhMe₂SiCl, chlorides of phosphorus PCl₅ or PCl₃, and sulphurchloride SCl₂.

[0032] Depending on the physical form of the Lewis acid employed,catalysis can be homogeneous or heterogeneous.

[0033] If it is liquid or soluble in a solvent, generally water, it canbe used in a supported form by depositing it on a mineral or organicsupport. To this end, the support can be selected from metal oxides suchas aluminium, silicon, titanium and/or zirconium oxides, clays, and moreparticularly kaolin, talc or montmorillonite, or from charcoal,optionally activated by a known treatment with nitric acid, acetyleneblack or organic polymers, for example the polyvinyl polymers polyvinylchloride (PVC), PVDC (polyvinylidene chloride), or polystyrene polymersthat can be functionalized with nitrile functions, or polyacrylicpolymers (in particular polyacrylonitrile).

[0034] The support can have any form, for example a powder, beads,granules, extrudates, etc.

[0035] The supported catalyst can be prepared using techniques that areknown to the skilled person.

[0036] To prepare the supported catalyst for use in the process of thepresent invention, conventional techniques for preparing supportedmetallic catalysts can be used that are known per se. Reference can inparticular be made to the preparation of the different catalystsdescribed in “Catalyse de contact: conception, preparation et mise enoeuvre des catalyseurs industrials” [Contact catalysis: design,preparation and use of industrial catalysts], J F LEPAGE, EditionTechnip (1978).

[0037] The catalyst can, for example, be prepared by introducing asupport into a solution prepared by dissolving at least one suitablecompound of the selected element(s); the active element or elementsis/are deposited on the support by distilling off the solvent, usuallywater, and the contact mass obtained is then dried.

[0038] In a conventional preparation mode, the compounds supplying theactive elements are deposited on the support by precipitating thecompounds in a manner that is known per se and then drying the contactmass.

[0039] In the description, the term “catalyst” means the catalystconstituted by the Lewis acid, or the supported catalyst

[0040] The amount of active phase represents 5% to 100% of the weight ofthe catalyst. In a supported catalyst, it represents 5% to 50%,preferably 5% to 20% by weight of the catalyst.

[0041] The catalysts can have different forms as used in the process ofthe invention: a powder, a formed product such as granules (for exampleextrudates or beads), or pellets, obtained by extrusion, moulding,compacting or any other known process.

[0042] Regarding the reagent employed, the hydroxylated organic compoundis a compound with low nucleophilicity. It has this characteristic withthe proviso that at least one electron-attracting group is present thatis sufficiently close to the hydroxyl group to deactivate it. Theelectron-attracting group can be present on the linear or cyclic,saturated or unsaturated hydrocarbon chain carrying the hydroxyl groupor it can be present on an aromatic carbocycle or heterocycle carried bya carbon atom carrying or close to (preferably in the α or β position)the atom carrying the hydroxyl group.

[0043] More precisely, it has formula (I):

R₁—O—H  (I)

[0044] in which formula (I):

[0045] R₁ represents a hydrocarbon group substituted with at least oneelectron-attracting group (G), containing 1 to 40 carbon atoms which maybe a linear or branched, saturated or unsaturated acyclic aliphaticgroup; a monocyclic or polycyclic, saturated or unsaturated or aromaticcarbocyclic or heterocyclic group; or a concatenation of said groups.

[0046] More particularly, the electron-attracting group (G) is one ofthe following atoms or groups:

[0047] an acyl group containing 2 to 20 carbon atoms, preferably acetyl;

[0048] a group with formula:

[0049] —X

[0050] —CX₃

[0051] —CF₂—CF₃;

[0052] —[CF₂]_(p)—CF₃;

[0053] —C_(p)H_(a)F_(b);

[0054] —COOM;

[0055] —COOR₃;

[0056] —CHO;

[0057] —SO₃-M;

[0058] —SO₃—R₃;

[0059] —SO₂—R₃;

[0060] —SO—CF₃;

[0061] —SO₂—CF₃;

[0062] —S—CF₃;

[0063] —NO₂;

[0064] —CN;

[0065] —N═C(R₃)₂;

[0066] —NH—CO—R₃;

[0067] —N⁺(R₃)₃;

[0068] —P(O)(OR₃)₂;

[0069] Si(R₃)₃

[0070] in which formulae, groups R₃, which may be identical ordifferent, represent a hydrogen atom or a linear or branched, saturatedor unsaturated alkyl group containing 1 to 20 carbon atoms; X representsa halogen atom, preferably a chlorine, bromine or fluorine atom; Mrepresents an alkali metal atom, preferably sodium or potassium; prepresents a number from 1 to 10, b represents a number from 3 to 21 anda+b—2p+1.

[0071] When group (G) is carried by an aromatic ring, this group can besubstituted for a hydrogen atom or it can be bonded to the cycle via agroup in the manner of —R₂-G; R₂ represents a covalent bond or adivalent, linear or branched, saturated or unsaturated hydrocarbon groupcontaining 1 to 4 carbon atoms such as methylene, ethylene, propylene,isopropylene or isopropylidene.

[0072] Preferred groups from those cited above are halogen atoms, thetrifluoromethyl group and the nitrile or nitro group.

[0073] More precisely, R₁ represents a hydrocarbon group containing 1 to20 carbon atoms, which may be a linear or branched, saturated orunsaturated acyclic aliphatic group; a monocyclic or polycyclic,saturated, unsaturated or aromatic carbocyclic or heterocyclic group; ora linear or branched, saturated or unsaturated aliphatic group carryinga cyclic substituent.

[0074] Preferably, R₁ represents a linear or branched, saturated acyclicaliphatic group preferably containing 1 to 12 carbon atoms, morepreferably 1 to 4 carbon atoms, The invention does not exclude thepresence of a single unsaturated bond on the hydrocarbon chain such asone or more double bonds, which may or may not be conjugated, or atriple bond.

[0075] The hydrocarbon chain can optionally be interrupted by aheteroatom (for example oxygen or sulphur) or by a functional group,provided that it does not react; the group —CO— can in particular becited.

[0076] The hydrocarbon chain can optionally carry one or moresubstituents (for example halogen, ester, aldehyde) provided that theydo not interfere with the sulphonylation reaction.

[0077] The linear or branched, saturated or unsaturated, acyclicaliphatic group can optionally carry a cyclic substituent. The term“cycle” means a saturated, unsaturated or aromatic carbocyclic orheterocyclic cycle.

[0078] The acyclic aliphatic group can be bonded to the cycle via acovalent bond, a heteroatom or a functional group such as oxy, carbonyl,sulphonyl, etc.

[0079] Examples of cyclic substituents that can be envisaged arecycloaliphatic, aromatic or heterocyclic substituents, in particularcycloaliphatic substituents containing 6 carbon atoms in the cycle orbenzenic compounds, said cyclic substituents themselves optionallycarrying any substituent provided that they do not interfere with thereactions occurring in the process of the invention. Particular mentioncan be made of alkyl or alkoxy groups containing 1 to 4 carbon atoms.

[0080] More particular examples of aliphatic groups carrying a cyclicsubstituent are aralkyl groups containing 7 to 12 carbon atoms, inparticular benzyl or phenylethyl.

[0081] In formula (I), R₁ can also represent a saturated or unsaturatedcarbocyclic group preferably containing 5 or 6 carbon atoms in thecycle; a saturated or unsaturated heterocyclic group containing 5 or 6carbon atoms in the cycle 1 including 1 or 2 heteroatoms such asnitrogen, sulphur or oxygen atoms; a monocyclic aromatic carbocyclic orheterocyclic group, preferably phenyl or pyridyl, or a condensed ornon-condensed polycyclic group, preferably naphthyl.

[0082] If R₁ includes a cycle, it can also be substituted. The number ofsubstituents is generally at most 4 per cycle, but is usually 1 or 2.

[0083] Preferably, R₁ is a linear or branched alkyl group containing 1to 12 carbon atoms, or the phenyl group.

[0084] More particularly, the process of the invention is applicable tofluorinated and perfluorinated aliphatic alcohols with formula (Ia):

R₁—O—H  (Ia)

[0085] in which formula (Ia), R₁ represents a fluorinated orperfluorinated alkyl chain containing 1 to 10 carbon atoms and 1 to 21fluorine atoms, preferably 3 to 21 fluorine atoms.

[0086] The process of the invention is particularly applicable tocompounds with formula (I) such as 2,2,2-trifluoroethanol,2,2-difluoroethanol, 1,1-difluoroethanol, pentafluoroethanol,hexafluoroisopropanol, pentafluorophenol, p-nitrophenol andp-trifluoromethylphenol.

[0087] The sulphonylating agent is a compound comprising at least one—SO₂R₄ type sulphonyl group in which R₄ represents a hydrocarbon groupcontaining 1 to 20 carbon atoms.

[0088] More particularly, it has the following formula (II):

[0089] in which formula (II):

[0090] R₄ represents a hydrocarbon group containing 1 to 20 carbonatoms;

[0091] Z represents:

[0092] a hydroxyl group or a halogen atom, preferably a chlorine orbromine atom;

[0093] a group —O—SO₂—R′₄, in which R′₄, which may be identical to ordifferent from R₄, has the meaning given for R₄.

[0094] Preferred sulphonylating agents have formula (II) in which Zrepresents a chlorine or bromine atom.

[0095] In formula (II), R₄ more particularly represents:

[0096] an alkyl group containing 1 to 10 carbon atoms, preferably 1 to 4carbon atoms, more preferably a methyl or ethyl group, optionallycarrying a halogen atom, a CF₃ group or an ammonium group N(R₅)₄, wheregroups R₅, which may be identical or different, representing an alkylgroup containing 1 to 4 carbon atoms;

[0097] a cycloalkyl group containing 3 to 8 carbon atoms, preferably acyclohexyl group;

[0098] an aryl group containing 6 to 12 carbon atoms, preferably aphenyl group optionally carrying an alkyl group containing 1 to 10carbon atoms, preferably 1 to 4 carbon atoms and more preferably amethyl or ethyl group, a halogen atom, a CF₃ group or a NO₂ group;

[0099] a group CX₃ in which X represents a fluorine, chlorine or bromineatom;

[0100] a group CF₂—CF₃;

[0101] a group C_(p)H_(a)F_(b) in which p represents a number from 1 to10, b a number from 3 to 21 and a+b=2p+1.

[0102] Preferred sulphonylating agents have formula (I) in which thegroup —SO₂—R₄ represents:

[0103] tosyl groups (p-toluenesulphonyl) —SO₂—C₆H₄—CH₃;

[0104] brosyl groups (p-bromobenzenesulphonyl) —SO₂—C₆H₄—Br;

[0105] nosyl groups (p-nitrobenzenesulphonyl) —SO₂—C₆H₄—NO₂;

[0106] mesyl groups (methanesulphonyl) —SO₂—CH₃;

[0107] betyl groups (ammonioalkanesulphonyl) —SO₂(CH₂)_(n)NMe₃ ⁺ where nis in the range 0 to 6;

[0108] triflyl groups (trifluoromethanesulphonyl) —SO₂—CF₃;

[0109] nonaflyl groups (nonafluorobutanesulphonyl) —SO₂—C₄F₉;

[0110] tresyl groups (2,2,2-trifluoroethanesulphonyl) —SO₂—CH₂—CF₃.

[0111] Preferred examples of sulphonylating agents that can be employedin particular are:

[0112] triflic anhydride;

[0113] methanesulphonyl chloride;

[0114] trifluormethanesulphonyl chloride;

[0115] benzenesulphonyl chloride;

[0116] p-toluenesulphonyl chloride.

[0117] In accordance with the process of the invention, a sulphonylatedorganic compound is obtained by reacting a hydroxylated organic compoundpreferably with formula (I) with a sulphonylating agent preferably withformula (II), in the presence of a Lewis acid comprising a metal ormetalloid cation M as defined above with an oxidation number n and acounter-ion to the metal cation which is symbolized by Y.

[0118] The catalytic entity involved in the process of the invention isrepresented by formulae (IV):

[0119] in which formulae:

[0120] R₄ and Z have the meanings given above;

[0121] M represents the metal or metalloid with oxidation number n;

[0122] Y represents the counter-ion to the cation M^(n+).

[0123] More precisely, the present invention encompasses the catalyticentity with formulae (IVa) as novel products:

[0124] in which formulae:

[0125] R₄ has the meaning given above.

[0126] In the process of the invention, the reaction between thehydroxylated compound and the sulphonylating agent is carried out in theliquid phase in the presence or absence of an organic solvent.

[0127] In a variation, the process of the invention consists of carryingout the reaction in an organic solvent.

[0128] A number of criteria govern the choice of solvent.

[0129] It must be inert under the conditions of the process of theinvention and must have a boiling point that is higher than the reactiontemperature.

[0130] Preferably, an aprotic and low polarity organic solvent is used.

[0131] Particular examples of solvents that are suitable for use in thepresent invention that can be cited are halogenated or non-halogenatedaliphatic or aromatic hydrocarbons.

[0132] More particular examples of aliphatic hydrocarbons that can becited are paraffins such as hexane, heptane, octane, nonane, decane,undecane, dodecane, tetradecane or cyclohexane and aromatichydrocarbons, more particularly aromatic hydrocarbons such as benzene,toluene, xylenes, cumene, or petroleum cuts constituted by a mixture ofalkylbenzenes in particular Solvesso® type cuts.

[0133] More particular examples of aliphatic or halogenated hydrocarbonsthat can be mentioned include perchlorinated hydrocarbons such astetrachloromethane, tetrachloroethylene and hexachloroethane; partiallychlorinated hydrocarbons such as dichloromethane, chloroform,1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2,2-tetrachloroethane,pentachloroethane, trichloroethylene, 1-chlorobutane,1,2-dichlorobutane; monochlorobenzene, 1,2-dichlorobenzene,1,3-dichlorobenzene, 1,4-dichlorobenzene, 1,2,4-trichlorobenzene ormixtures of different chlorobenzenes; bromoform, bromoethane or1,2-dibromoethane; monobromobenzene or mixtures of monobromobenzene withone or more dibromobenzenes; and 1-bromonapthalene.

[0134] It is also possible to use a mixture of organic solvents.

[0135] Preferred solvents are dichloromethane and toluene.

[0136] As mentioned above, the hydroxylated compound is reacted with asulphonylating agent, optionally in the presence of a reaction solventas defined and in the presence of a Lewis acid type catalyst.

[0137] The ratio between the number of moles of sulphonylating agent andthe number of moles of hydroxylated compound can be in the range 0.9 to2, and is preferably in the range 1.0 to 1.2.

[0138] The quantity of catalyst used in the process of the invention canvary widely. It can represent 0.01% to 20%, preferably 0.05% to 10% andmore preferably 0.1% to 2%, by weight with respect to the hydroxylatedcompound employed.

[0139] When an organic solvent is employed, it is used in a quantitythat is generally selected so that the concentration of the productobtained is in the range 10% to 60%, preferably in the range 20% to 30%.

[0140] The temperature at which the sulphonylation reaction is carriedout depends on the reactivity of the starting substrate and on that ofthe sulphonylating agent.

[0141] It is between 20° C. and 150° C., preferably in the range 70° C.to 100° C.

[0142] Generally, the reaction is carried out at atmospheric pressure,but lower or higher pressures are also suitable. Autogenous pressure isemployed when the reaction temperature is higher than the boiling pointof the reagents and/or products.

[0143] In a preferred variation of the process of the invention, it iscarried out in a controlled inert gas atmosphere. A rare gas atmospherecan be established, preferably argon, but it is cheaper to use nitrogen.

[0144] From a practical viewpoint, the process can be carried outbatchwise or continuously.

[0145] In a first variation, the sulphonylating agent and the Lewis acidtype catalyst are charged.

[0146] After bringing the reagents into contact, the reaction mixture isheated to the desired temperature with stirring.

[0147] The hydroxylated compound is then added, preferably slowly.

[0148] Stirring is continued until all of the reagents have beenconsumed, as monitored by an analytical method, for example gaschromatography.

[0149] At the end of the reaction, a liquid phase that comprises thesulphonylated compound is obtained; it can be recovered conventionally,for example by distillation or crystallization.

[0150] After separating the sulphonylated compound by distillation, adistillation liquor is obtained comprising the catalyst and which can berecycled a number of times.

[0151] It is also possible to separate out the catalyst at the end ofthe reaction. If it is insoluble, it can be separated using asolid/liquid separation technique, preferably by filtering.

[0152] In the case of a soluble catalyst, it is eliminated by treatingthe medium with a complexing agent, for example tartaric acid or sodiumcarbonate.

[0153] When preparing 2,2,2-trifluoroethylmethanesulphonate from2,2,2-trifluoroethanol and mesyl chloride, the hydrochloric acid formedis trapped in a basic column, preferably caustic soda, then the productformed is recovered by distillation.

[0154] In the second variation, the reaction is carried out continuouslyin a tube reactor comprising the solid catalyst disposed in a fixed bed.

[0155] The hydroxylated compound and the sulphonylating agent can beintroduced separately or mixed in the reactor.

[0156] They can also be introduced into a solvent as mentioned above.

[0157] The liquid phase obtained is treated as described above.

[0158] A sulphonylated compound with formula (III) is obtained:

[0159] in which formula (III), R₁ and R₄ have the meanings given above.

[0160] The compound with formula (III) can be used as an intermediateproduct for the preparation of ether-oxides.

[0161] Compound (III) can bind a group R₁ to a hydroxylated organiccompound (in particular a hydroxylated aromatic compound) which can berepresented by the formula (V);

R₆—O—H  (V)

[0162] in which formula, R₆ has the meanings given for R₁, withoutnecessitating the presence of an electron-attracting group.

[0163] In a further aspect, the invention provides a process forpreparing an ether-oxide with formula (VI):

R₆—O—R₁  (VI)

[0164] in which formula, R₆, which may be identical to or different fromR₁, has the meanings given for R₁ without the necessity for the presenceof an electron-attracting group, characterized in that it consists ofpreparing a compound with formula (III) obtained in accordance with theprocess of the invention then reacting the product obtained with ahydroxylated compound with formula (V) in the presence of a base.

[0165] The invention can produce symmetrical ether-oxides if R₆ isidentical to R₁ or asymmetrical ether-oxides if R₆ is different from R₁.

[0166] In accordance with the invention, a compound with formula (VI) isprepared in which R₆ represents an aromatic cycle and which has thefollowing formula:

[0167] in which formula (VIa), R₁ has the meaning given above and Arepresents the residue of a cycle forming all or a portion of amonocyclic or polycyclic, aromatic carbocyclic or heterocyclic system.

[0168] The invention is particularly applicable to aromatic compoundswith formula (VIa) in which A is a residue of a cyclic compoundpreferably containing at least 4 atoms in the cycle, which may besubstituted, and representing at least one of the following cycles:

[0169] a monocyclic or polycyclic aromatic carbocycle;

[0170] a monocyclic or polycyclic aromatic heterocycle containing atleast one of heteroatoms O, N or S;

[0171] Without limiting the scope of the invention, residue A, which maybe substituted, can represent the residue:

[0172] 1°—of a monocyclic or polycyclic aromatic carbocyclic compound.

[0173]  The term “polycyclic carbocyclic compound” means:

[0174] a compound constituted by at least 2 aromatic carbocycles andforming between them ortho- or ortho- and pericondensed systems;

[0175] a compound constituted by at least 2 carbocycles one of which isaromatic and forming between them ortho- or ortho- and pericondensedsystems.

[0176] 2°—of a monocyclic or polycyclic aromatic heterocyclic compound.

[0177]  The term “polycyclic heterocyclic compound” means:

[0178] a compound constituted by at least 2 heterocycles containing atleast one heteroatom in each cycle at least one of the two cycles beingaromatic and forming between them ortho- or ortho- and pericondensedsystems;

[0179] a compound constituted by at least one hydrocarbon cycle and atleast one heterocycle at least one of the cycles being aromatic andforming between them ortho- or ortho- and pericondensed systems.

[0180] 3°—of a compound constituted by a concatenation of cycles, asdefined in paragraphs 1 and/or 2 bonded together via a covalent bond,via an alkylene or alkylidene group containing 1 to 4 carbon atoms,preferably a methylene or isopropylidene group or via an atom or groupssuch as oxygen, a carbonyl group or a carboxy group, etc. . . .

[0181] More particularly, residue A, which may be substituted,represents the residue:

[0182] of an aromatic, carbocyclic monocyclic compound such as benzene,for example;

[0183] of an aromatic condensed polycyclic compound such as naphthalene,for example;

[0184] of an aromatic carbocyclic non condensed polycyclic compound suchas phenoxybenzene;

[0185] of a partially aromatic carbocyclic condensed polycyclic compoundsuch as tetrahydronaphthalene, 1,2-methylene dioxybenzene, for example;

[0186] of a partially aromatic, carbocyclic non condensed polycycliccompound such as cyclohexylbenzene, for example;

[0187] of an aromatic heterocyclic monocyclic compound such as pyridine,furan or thiophene;

[0188] of a partially heterocyclic, aromatic condensed polycycliccompound such as quinoline, indole or benzofuran;

[0189] of a partially heterocyclic, aromatic non condensed polycycliccompound such as phenylpyridines or naphthylpyridines;

[0190] of a partially heterocyclic, partially aromatic, condensedpolycyclic compound such as tetrahydroquinoline, for example;

[0191] of a partially heterocyclic, partially aromatic, non condensedpolycyclic compound such as cyclohexylpyridine, for example.

[0192] The invention does not exclude the presence of a substituent onthe cycle of any nature provided that it does not interfere with thereaction. Alkyl or alkoxy groups containing 1 to 4 carbon atoms can becited, inter alia.

[0193] The reaction of the compound with formula (V) and compound withformula (III) is an O-alkylation reaction which is carried out in thepresence of a base.

[0194] Thus, the process of the invention employs a base which may bemineral or organic.

[0195] Preferably, a strong base is selected, i.e., a base with a pKa of10 or more: the pKa is defined as the co logarithm of the dissociationconstant of the conjugated acid measured in an aqueous medium at 25° C.

[0196] Mineral bases such as alkali metal salts are particularlysuitable for use in the process of the invention, such as an alkalimetal hydroxyide, which can be sodium or potassium hydroxide; or analkali metal carbonate, preferably potassium carbonate.

[0197] It is also possible to use a quaternary ammonium hydroxide.

[0198] Examples of quaternary ammonium hydroxides that are preferablyemployed are tetraalkylammonium or trialkylbenzylammonium hydroxideswherein the alkyl groups, which may be identical or different, representa linear or branched alkyl chain containing 1 to 12 carbon atoms,preferably 1 to 6 carbon atoms. Preferably, tetramethylammoniumhydroxide, tetraethylammonium hydroxide, tetrabutylammonium hydroxide ortrimethylbenzylammonium hydroxide are used.

[0199] A metal alcoholate can also be used, for example sodium orpotassium methylate or potassium tert-butylate.

[0200] For reasons of economy, sodium hydroxide or potassium carbonateis used as the selected base.

[0201] The concentration of basic starting solution is not critical. Thealkali metal hydroxide solution is employed at a concentration that isgenerally in the range 10% to 50% by weight.

[0202] The quantity of base introduced into the reaction medium is suchthat the ratio between the number of moles of base, expressed as OH⁻,and the number of moles of compound (V) is in the range 1 to 2,preferably in the range 1 to 1.5.

[0203] The reaction is carried out in the presence of an organicsolvent, preferably a polar organic solvent.

[0204] Examples of polar aprotic organic solvents that can also beemployed in the process of the invention that can more particularly becited are nitro compounds, for example nitromethane, nitroethane,1-nitropropane, 2-nitropropane or mixtures thereof, or nitrobenzene;aliphatic or aromatic nitrites such as acetonitrile, propionitrile,benzonitrile or benzyl cyanide; linear or cyclic carboxamides such asN,N-dimethylacetamide (DMAC), N,N-diethylacetamide, dimethylformamide(DMF), diethylformamide or 1-methyl-2-pyrrolidone (NMP);dimethylsulphoxide (DMSO); tetramethylenesulpholane (sulpholane); andhexamethylphosphotriamide (HMPT).

[0205] The organic solvent can also be an aliphatic, cycloaliphatic oraromatic ether-oxide, more particularly dipropyl oxide, diisopropyloxide, dibutyl oxide, methyltertiobutyl ether, ethylene glycoldimethylether (glyme), diethylene glycol dimethylether (diglyme); phenyloxide; dioxane, or tetrahydrofuran (THF).

[0206] Preferred solvents are DMAC and DMF.

[0207] It is also possible to use a mixture of organic solvents.

[0208] The different reagents and substrates are used in the quantitiesdefined below.

[0209] The concentration of compound with formula (V), preferably (Va),employed in the solvent can vary widely. Generally, the concentration ofsaid compound is in the range 20% to 30% of the solvent weight.

[0210] The basification reaction is carried out between 0° C. and 60°C., preferably between 0° C. and 20° C.

[0211] It is generally carried out at atmospheric pressure.

[0212] From a practical viewpoint, the salt of the compound with formula(V) is prepared by reacting it with the base.

[0213] The water formed is eliminated and then the sulphonylatedcompound is added.

[0214] The O-alkylation reaction is carried out between 60° C. and 160°C., preferably between 120° C. and 140° C.

[0215] The O-alkylated compound with formula (VI) is obtained.

[0216] The reaction solvent is evaporated off and the product obtainedis recovered conventionally, for example by distillation orcrystallization.

[0217] Examples of implementations of the process of the invention willnow be given by way of non-limiting illustration.${{Yield}\quad ({RR})} = {\frac{{number}\quad {of}\quad {moles}\quad {of}\quad {sulphonylated}\quad {compound}\quad {formed}}{{number}\quad {of}\quad {moles}\quad {of}\quad {hydroxylated}\quad {compound}\quad {{introducted}.}}\%}$

EXAMPLE 1 Preparation of 2,2,2-trifluoroethylmethanesulphonate (TFEMes)in a Semi-Continuous Process

[0218] The following were successively charged into a reactor: 600 g ofmesyl chloride (CMS, reference compound) and 24 g of SbCl₅.

[0219] The mixture was stirred and heated to 75-85° C.

[0220] 552 g of 2,2,2-trifluoroethanol (TFE) was then slowly added,keeping the temperature between 75° C. and 80° C.

[0221] The reaction mixture was stirred for about 2 hours more afteradding the TFE.

[0222] The crude reaction medium was then cooled to ambient temperaturebefore being distilled under reduced pressure (20-50 mbars, boilingpoint of TFEMes=99° C./35 mm Hg).

[0223] After distillation, 828 g of TFEMes was obtained, giving a yieldof 89%.

EXAMPLE 2 Preparation of 2,2,2-trifluoroethylmethanesulphonate (TFEMes)in a Semi-Continuous Process

[0224] The following were successively charged into a reactor: 600 z of2,2,2-trifluoroethanol (TFE, reference compound) and 90 g of ZnCl₂.

[0225] The mixture was stirred and heated to 75-85° C. 738 g of mesylchloride (CMS) was then slowly added, keeping the temperature between75° C. and 85° C. for about 13 hours.

[0226] The crude reaction medium was then cooled to ambient temperaturebefore being distilled under reduced pressure (20-50 mbars, boilingpoint of TFEMes=99° C./35 mm Hg).

[0227] After distillation, 714 g of TFEMes was obtained, giving a yieldof 67%.

EXAMPLE 3 Preparation of 2,2,2-trifluoroethylmethanesulphonate (TFEMes)in a Batch Process

[0228] The following were successively charged into a reactor: 750 g ofmesyl chloride (CMS), 96 g of TeCl₄ and 600 g of and 24 g of2,2,2-trifluoroethanol (TFE, reference compound).

[0229] The mixture was stirred and heated to 75-85° C. for about 9hours.

[0230] The crude reaction medium was then cooled to ambient temperaturebefore being distilled under reduced pressure (20-50 mbars, boilingpoint of TFEMes=99° C./35 mm Hg).

[0231] After distillation, 450 g of TFEMes was obtained, giving a yieldof 42%.

EXAMPLE 4 Preparation of Phenyl 2,2,2-trifluoroethyl Oxide

[0232] Starting from 2,2,2-trifluoroethylnethanesulphonate (TFEMes)prepared using any of Examples 1-3, ethers such as phenyl oxide and2,2,2-trifluoroethyl can be obtained as follows:

[0233] 600 g of phenol (reference compound) was dissolved in 4920 g ofdimethylacetamide (DMAC) in a reactor.

[0234] The solution obtained was heated to 50° C. then 1.3 g of anaqueous 50% by weight KOH solution was slowly added.

[0235] The mixture was kept at 60° C. for about 30 minutes after addingthe KOH solution.

[0236] The water formed was evaporated off under reduced pressure.

[0237] 1236 g of TFEMes was then slowly added (about 2 hours) to thereaction mixture, keeping the temperature of the reaction mixturebetween 120° C. and 140° C.

[0238] Following addition, the temperature (120-140° C.) and stirringwere maintained for about 3 hours.

[0239] The solvent was then distilled off under reduced pressure and theconcentrate was taken up in 3600 g of water and 3000 g of toluene.

[0240] The organic phase was then washed with 3600 g of water, driedover K₂CO₃, filtered, and the solvents were evaporated off under reducedpressure.

[0241] The concentrate yielded 80-85% by weight of the expected product.

EXAMPLE 5 Preparation of1,1,1,3,3,3-hexafluoroisopropylmethanesulphonate (HFIPMes) in a BatchProcess

[0242] The following were successively charged into a reactor: 600 g ofmesyl chloride (CMS, reference compound), 24 g of SbCl₅ and 880 g of1,1,1,3,3,3-hexafluoro-2-propanol (HFIP).

[0243] The mixture was stirred and heated to 55° C. for about 9 hours.

[0244] The crude reaction medium was then cooled to ambient temperaturebefore being distilled under reduced pressure (20-50 mbars, boilingpoint of TFEMes=99° C./35 mm Hg).

[0245] After distillation, 1160 g of HFIPMes was obtained, giving ayield of 90%.

EXAMPLE 6 Preparation of 2,2,2-trichloroethylmethanesulphonate (TCEMes)in a Batch Process

[0246] The following were successively charged into a reactor: 600 g ofmesyl chloride (CMS, reference compound), 24 g of SbCl₅ and 783 g of2,2,2-trichloroethanol (TCE).

[0247] The mixture was stirred and heated to 85-90° C. for about 8hours.

[0248] The crude reaction medium was then assayed by gas chromatographywith an internal reference, which indicated that the yield of TCEMes was48%.

EXAMPLE 7 Preparation of 2,2-difluoroethylmethanesulphonate (DFEMes) ina Batch Process

[0249] The following were successively charged into a reactor: 6 g ofmesyl chloride (CMS, reference compound), 0.24 g of SbCls of and 4.3 gof 2,2,-difluoroethanol (DFE).

[0250] The mixture was stirred and heated to 80-85° C. for about 8hours.

[0251] The crude reaction medium was then assayed by gas chromatographywith an internal reference, which indicated that the yield of DFEMes was11%.

EXAMPLE 8 Preparation of 2-fluoroethylmethanesulphonate (MFEMes) in aBatch Process

[0252] The following were successively charged into a reactor: 6 g ofmesyl chloride (CMS, reference compound), 0.24 g of SbCl₅ of and 6 g of3,3,3-trifluoropropanol (TFP).

[0253] The mixture was stirred and heated to 85-90° C. for about 8hours.

[0254] The crude reaction medium was then assayed by gas chromatographywith an internal reference, which indicated that the yield of MFEMes was44%.

EXAMPLE 9 Preparation of 3,3,3-trifluoropropylmethanesulphonate (mNPMes)in a Batch Process

[0255] The following were successively charged into a reactor: 6 g ofmesyl chloride (CMS, reference compound), 0.24 g of SbCl₅ of and 7.3 gof 3-nitrophenol (mNP).

[0256] The mixture was stirred and heated to 85-90° C. for about 8hours.

[0257] The crude reaction medium was then assayed by gas chromatographywith an internal reference, which indicated that the yield of mNPMes was34%.

1. A process for sulphonylating a hydroxylated organic compound,characterized in that it consists of reacting said compound with asulphonylating agent in the presence of an effective quantity of a Lewisacid.
 2. A process according to claim 1, characterized in that the Lewisacid is a compound comprising a metal or metalloid cation that acceptselectron pairs defined as “borderline” in the “hard-soft” classificationdefined by R PEARSON: the term “borderline” as used in the inventionincluding hard or soft cations with the exception of the hardest andsoftest cations.
 3. A process according to claim 2, characterized inthat the “borderline” cation employed has an oxidation number or atleast +2, preferably +3, +4 or +5.
 4. A process according to claim 2 orclaim 3, characterized in that the cation is a metal or metalloid cationof metallic or metalloid elements from groups (IIb), (IVb), (Vb) and(VIb) of the periodic table.
 5. A process according to claim 2,characterized in that the cation is selected from the following cations:Zn²⁺, Sn²⁺, Sn⁴⁺, Sb⁵⁺, Bi³⁺, Te⁴⁺, preferably Sb⁵⁺.
 6. A processaccording to claim 1, characterized in that the Lewis acid is a compoundcomprising an anion selected from the following anions: hard anions,such as SO₄ ²⁻, CH₃COO⁻, C₆H₅COO⁻, CH₃SO₃ ⁻, CF₃SO₃ ⁻, or CF₃C₆H₄SO₃ ⁻,and borderline anions such as Cl⁻, Br⁻, NO₂ ⁻ or SO₃ ²⁻.
 7. A processaccording to claim 6, characterized in that the anion is selected fromCl⁻ and Br⁻.
 8. A process according to claim 4, characterized in thatthe Lewis acid is an organic salt such as the acetate, propionate,benzoate, methanesulphonate, trifluoromethanesulphonate of metal ormetalloid elements from said groups from the periodic table and/or aninorganic salt such as the chloride, bromide, iodide, sulphate or oxide,and analogous products of the metal or metalloid elements from saidgroups.
 9. A process according to claim 1, characterized in that theLewis acid is selected from metal halides, more particularly antimony(V), tin (II) or (IV), zinc (II), bismuth (III) or tellurium (IV)chloride or bromide.
 10. A process according to claim 1, characterizedin that the catalyst is deposited on a mineral or organic support,preferably selected from metal oxides such as aluminium, silicon,titanium and/or zirconium oxides, clays and more particularly kaolin,talc or montmorillonite, or from charcoals, optionally activated bytreatment with nitric acid, acetylene black or organic polymers,preferably polyvinyl or polystyrene polymers.
 11. A process according toclaim 1, characterized in that the hydroxylated organic compound has atleast one electron-attracting group that is sufficiently close to thehydroxyl group to deactivate it; the electron-attracting group possiblybeing present on the linear or cyclic, saturated or unsaturatedhydrocarbon chain carrying the hydroxyl group or present on an aromaticcarbocycle or heterocycle carried by a carbon atom carrying or close tothat carrying the hydroxyl group.
 12. A process according to one ofclaims 1 to 11, characterized in that the hydroxylated organic compoundhas formula (I): R₁—O—H  (I) in which formula (I): R₁ represents ahydrocarbon group substituted with at least one electron-attractinggroup (G), containing 1 to 40 carbon atoms, which may be a linear orbranched, saturated or unsaturated acyclic aliphatic group; a monocyclicor polycyclic, saturated or unsaturated or aromatic carbocyclic orheterocyclic group; or a concatenation of said groups.
 13. A processaccording to claim 12, characterized in that the hydroxylated organiccompound has at least one electron-attracting group (G) selected fromone of the following atoms or groups: an acyl group containing 2 to 20carbon atoms, preferably acetyl; a group with formula: —X —CX₃ —CF₂-CF₃;—[CF₂]_(p)—CF₃; —C_(p)H_(a)F_(b); —COOM; —COOR₃; —CHO; —SO₃—M; —SO₃—R₃;—SO₂—R₃; —SO—CF₃; —SO₂—CF₃; —S—CF₃ —NO₂; —CN; —N═C(R₃)₂; —NH—CO—R₃;—N⁺(R₃)₃; ——P(O)(OR₃)₂; Si(R₃)₃ in which formulae, groups R₃, which maybe identical or different, represent a hydrogen atom or a linear orbranched, saturated or unsaturated alkyl group containing 1 to 20 carbonatoms; X represents a halogen atom, preferably a chlorine, bromine orfluorine atom; M represents an alkali metal atom, preferably sodium orpotassium; p represents a number from 1 to 10, b represents a numberfrom 3 to 21 and a+b=2p+1.
 14. A process according to claim 13,characterized in that the hydroxylated organic compound has formula (I)in which R₁ represents: a linear or branched acyclic aliphatic group; anacyclic aliphatic group carrying a cyclic substituent, optionallysubstituted, preferably a benzene ring, which can be bonded to the cyclevia a covalent bond, a heteroatom or a functional group; a saturated orunsaturated carbocyclic group preferably containing 5 or 6 carbon atomsin the cycle; a saturated or unsaturated heterocyclic group containing 5or 6 atoms in the cycle including 1 or 2 heteroatoms such as nitrogen,sulphur or oxygen atoms; a monocyclic aromatic carbocyclic orheterocyclic group, preferably phenyl or pyridyl, or a condensed or noncondensed polycyclic group, preferably naphthyl.
 15. A process accordingto one of claims 12 to 14, characterized in that the hydroxylatedorganic compound has formula (I) in which R₁ represents a linear orbranched alkyl group containing 1 to 12 carbon atoms, preferably 1 to 6carbon atoms; the hydrocarbon chain optionally being interrupted by aheteroatom or by a functional group and/or carrying a substituent.
 16. Aprocess according to claim 1, characterized in that the hydroxylatedorganic compound has formula (Ia): R₁—O—H  (Ia) in which formula (Ia),R₁ represents a fluorinated or perfluorinated alkyl chain containing 1to 10 carbon atoms and 1 to 21 fluorine atoms, preferably 3 to 21fluorine atoms.
 17. A process according to claim 1, characterized inthat the hydroxylated organic compound is selected from:2,2,2-trifluoroethanol, 2,2-difluoroethanol, 1,1-difluoroethanol,pentafluoroethanol, hexafluoroisopropanol, pentafluorophenol,p-nitrophenol and p-trifluoromethylphenol.
 18. A process according toclaim 1, characterized in that the sulphonylating agent is a compoundcomprising at least one —SO₂R₄ type sulphonyl group in which R₄represents a hydrocarbon group containing 1 to 20 carbon atoms.
 19. Aprocess according to claim 18, characterized in that the sulphonylatingagent is a compound with the following formula (II):

in which formula (II): R₄ represents a hydrocarbon group containing 1 to20 carbon atoms; Z represents: a hydroxyl group or a halogen atom,preferably a chlorine or bromine atom; a group —O—SO₂—R′₄, in which R′₄,which may be identical to or different from R₄, has the meaning givenfor R₄.
 20. A process according to claim 19, characterized in that thesulphonylating agent is a compound with formula (II) in which Zrepresents a chlorine or bromine atom.
 21. A process according to claim19, characterized in that the sulphonylating agent is a compound withformula (II) in which R₄ represents: an alkyl group containing 1 to 10carbon atoms, preferably 1 to 4 carbon atoms, more preferably a methylor ethyl group, which optionally carries a halogen atom, a CF₃ group oran ammonium group N(R₅)₄, where groups R₅, which may be identical ordifferent, represent an alkyl group containing 1 to 4 carbon atoms; acycloalkyl group containing 3 to 8 carbon atoms, preferably a cyclohexylgroup; an aryl group containing 6 to 12 carbon atoms, preferably aphenyl group optionally carrying an alkyl group containing 1 to 10carbon atoms, preferably 1 to 4 carbon atoms and more preferably amethyl or ethyl group, a halogen atom, a CF₃ group or a NO₂ group; agroup CX₃ in which X represents a fluorine, chlorine or bromine atom; agroup CF₂—CF₃; a group C_(p)H_(a)F_(b) in which p represents a numberfrom 1 to 10, b a number from 3 to 21 and a+b=2p+1.
 22. A processaccording to claim 19, characterized in that the sulphonylating agent isa compound with formula (II) in which the group —SO₂—R₄ represents:tosyl groups (p-toluenesulphonyl) —SO₂—C₆H₄—CH₃; brosyl groups(p-bromobenzenesulphonyl) —SO₂—C₆H₄—Br; nosyl groups(p-nitrobenzenesulphonyl) —SO₂—C₆H₄—NO₂; mesyl groups (methanesulphonyl)—SO₂—CH₃; betyl groups (ammonioalkanesulphonyl) —SO₂(CH₂)_(n)NMe₃ ⁺where n is in the range 0 to 6; triflyl groups(trifluoromethanesulphonyl) —SO₂—CF₃; nonaflyl groups(nonafluorobutanesulphonyl) —SO₂—C₄F₉; tresyl groups(2,2,2-trifluoroethanesulphonyl) —SO₂—CH₂—CF₃.
 23. A process accordingto claim 18, characterized in that the sulphonylating agent is selectedfrom: triflic anhydride; methanesulphonyl chloride;trifluormethanesulphonyl chloride; benzenesulphonyl chloride;p-toluenesulphonyl chloride.
 24. A process according to one of claims 1to 23, characterized in that the reaction between the hydroxylatedcompound and the sulphonylating agent is carried out in the liquidphase, in the presence or absence of an organic solvent, preferably anaprotic or low polarity organic solvent.
 25. A process according to oneof claims 1 to 24, characterized in that the ratio between the number ofmoles of sulphonylating agent and the number of moles of hydroxylatingagent is in the range 0.9 to 2, and is preferably in the range 1.0 to1.2.
 26. A process according to one of claims 1 to 25, characterized inthat the quantity of catalyst represents 0.01% to 20%, preferably 0.05%to 10% and more preferably 0.1% to 2% of the weight of the hydroxylatedcompound employed.
 27. A process according to one of claims 1 to 26,characterized in that the temperature at which the sulphonylationreaction is carried out is in the range 20° C. to 150° C., preferably inthe range 70° C. to 100° C.
 28. A process according to one of claims 1to 27, characterized in that the sulphonylating agent and the Lewis acidtype catalyst are charged and the reaction mixture is stirred and heatedto the desired temperature, then the hydroxylated compound is added,preferably slowly.
 29. A process according to one of claims 1 to 28,characterized in that a sulphonylated compound with the followingformula (III) is obtained:

in which formula (III), R₁ has the meaning defined in one of claims 12,14, 15 and 16 and R₄ has the meaning defined in one of claims 18, 19, 21and
 22. 30. A process according to one of claims 1 to 29, characterizedin that 2,2,2-trifluoroethylmethanesulphonate is obtained from2,2,2-trifluoroethanol and mesyl chloride, in the presence of antimony(V) chloride.
 31. A process for preparing an ether-oxide with formula(VI): R₆—O—R₁  (VI) in which formula, R₆, which may be identical to ordifferent from R₁, has the meaning given for R₁ without the necessityfor the presence of an electron-attracting group, characterized in thatit consists of: preparing a compound with formula (III) obtained inaccordance with the process defined in one of claims 1 to 30; reactingthe compound with formula (III) with a hydroxylated organic compoundwith formula (V) in the presence of a base: R₆—O—H  (V)  in whichformula R₆ has the meaning given above.
 32. A process according to claim31, characterized in that the compound with formula (VI) is prepared inwhich R₆ represents an aromatic cycle and which has the followingformula:

in which formula (VIa), R₁ has the meaning given above and A representsthe residue of a cycle forming all or a portion of a monocyclic orpolycyclic, aromatic carbocyclic or heterocyclic system.
 33. A processaccording to claim 32, characterized in that the hydroxylated aromaticcompound has formula (VIa) in which the residue A, which is optionallysubstituted, represents the residue: of an aromatic, carbocyclicmonocyclic compound such as benzene, for example; of an aromaticcondensed polycyclic compound such as naphthalene, for example; of anaromatic carbocyclic non condensed polycyclic compound such asphenoxybenzene; of a partially aromatic, carbocyclic condensedpolycyclic compound such as tetrahydronaphthalene, 1,2-methylenedioxybenzene, for example; of a partially aromatic, carbocyclic, noncondensed polycyclic compound such as cyclohexylbenzene, for example; ofan aromatic heterocyclic monocyclic compound such as pyridine, furan orthiophene; of a partially heterocyclic, aromatic condensed polycycliccompound such as quinoline, indole or benzofuran; of a partiallyheterocyclic, aromatic non condensed polycyclic compound such asphenylpyridines or naphthylpyridines; of a partially heterocyclic,partially aromatic, condensed polycyclic compound such astetrahydroquinoline, for example; of a partially heterocyclic, partiallyaromatic, non condensed, polycyclic compound such as cyclohexylpyridine,for example.
 34. A process according to claim 31, characterized in thatthe reaction of the compound with formula (V) and the compound withformula (III) is an O-alkylation reaction carried out in the presence ofa base which may be a mineral base such as an alkali metal salt,preferably an alkali metal hydroxide which may be sodium or potassiumhydroxide; an alkali metal carbonate, preferably potassium; a quaternaryammonium hydroxide; or a metallic alcoholate, preferably sodium orpotassium methylate or potassium tert-butylate.
 35. A process accordingto claim 31, characterized in that the reaction is carried out in thepresence of an organic solvent, preferably a polar organic solvent andmore preferably DMAC or DMF.
 36. A process according to claim 31,characterized in that the O-alkylation reaction is carried out between60° C. and 160° C., preferably between 120° C. and 140° C.
 37. Acatalytic entity having one of formulae (IVa):

in which formulae: R₄ has the meanings defined above.